> ## Documentation Index
> Fetch the complete documentation index at: https://docs.e-invoice.be/llms.txt
> Use this file to discover all available pages before exploring further.
# Advanced invoicing
> Add allowances (discounts) and charges (fees) to an invoice at document level and at line level.
## Overview
An invoice can contain two types of adjustment:
* **Allowances** (discounts) decrease the invoice amount.
* **Charges** (fees) increase the invoice amount.
You can apply each type at two levels:
1. **Document level**: the adjustment applies to the full invoice (for example an early payment discount or a handling fee).
2. **Line level**: the adjustment applies to one line item (for example a bulk discount on one product).
The API calculates the totals of the document from the lines, the allowances and the charges. [Invoice totals and calculations](/guides/invoice-totals) gives the formulas.
## Send the request
All request bodies on this page go to the same two endpoints: `POST /api/validate/json` (to examine the body) and `POST /api/documents/` (to create the document). Only the JSON body changes. The request below creates the basic invoice; replace its body with a body from this page.
```bash cURL theme={null}
curl -X POST "https://api.e-invoice.be/api/documents/" \
-H "Authorization: Bearer $E_INVOICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"document_type": "INVOICE",
"invoice_id": "INV-2026-001",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"purchase_order": "PO-12345",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"vendor_email": "billing@e-invoice.be",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Professional services",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"subtotal": 1000.00,
"total_tax": 210.00,
"invoice_total": 1210.00,
"amount_due": 1210.00,
"payment_term": "Payment within 30 days",
"payment_details": [
{
"iban": "BE68539007547034",
"swift": "GEBABEBB",
"payment_reference": "INV-2026-001"
}
]
}'
```
```javascript Node.js theme={null}
const invoice = {
document_type: "INVOICE",
invoice_id: "INV-2026-001",
invoice_date: "2026-10-01",
due_date: "2026-10-31",
currency: "EUR",
purchase_order: "PO-12345",
vendor_name: "E-INVOICE BV",
vendor_tax_id: "BE1018265814",
vendor_address: "Brusselsesteenweg 119/A, 1980 Zemst, BE",
vendor_email: "billing@e-invoice.be",
customer_name: "OpenPeppol VZW",
customer_tax_id: "BE0848934496",
customer_address: "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
items: [
{
description: "Professional services",
quantity: 10,
unit: "C62",
unit_price: 100.00,
amount: 1000.00,
tax_rate: "21.00"
}
],
subtotal: 1000.00,
total_tax: 210.00,
invoice_total: 1210.00,
amount_due: 1210.00,
payment_term: "Payment within 30 days",
payment_details: [
{
iban: "BE68539007547034",
swift: "GEBABEBB",
payment_reference: "INV-2026-001"
}
]
};
const response = await fetch("https://api.e-invoice.be/api/documents/", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.E_INVOICE_API_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify(invoice),
});
const result = await response.json();
if (!response.ok) {
throw new Error(`HTTP ${response.status}: ${JSON.stringify(result)}`);
}
console.log(result);
```
```python Python theme={null}
import os
import requests
invoice = {
"document_type": "INVOICE",
"invoice_id": "INV-2026-001",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"purchase_order": "PO-12345",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"vendor_email": "billing@e-invoice.be",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Professional services",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"subtotal": 1000.00,
"total_tax": 210.00,
"invoice_total": 1210.00,
"amount_due": 1210.00,
"payment_term": "Payment within 30 days",
"payment_details": [
{
"iban": "BE68539007547034",
"swift": "GEBABEBB",
"payment_reference": "INV-2026-001"
}
]
}
response = requests.post(
"https://api.e-invoice.be/api/documents/",
headers={"Authorization": f"Bearer {os.environ['E_INVOICE_API_KEY']}"},
json=invoice,
timeout=30,
)
if not response.ok:
raise SystemExit(f"HTTP {response.status_code}: {response.text}")
print(response.json())
```
```php PHP theme={null}
"INVOICE",
"invoice_id" => "INV-2026-001",
"invoice_date" => "2026-10-01",
"due_date" => "2026-10-31",
"currency" => "EUR",
"purchase_order" => "PO-12345",
"vendor_name" => "E-INVOICE BV",
"vendor_tax_id" => "BE1018265814",
"vendor_address" => "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"vendor_email" => "billing@e-invoice.be",
"customer_name" => "OpenPeppol VZW",
"customer_tax_id" => "BE0848934496",
"customer_address" => "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items" => [
[
"description" => "Professional services",
"quantity" => 10,
"unit" => "C62",
"unit_price" => 100.00,
"amount" => 1000.00,
"tax_rate" => "21.00"
]
],
"subtotal" => 1000.00,
"total_tax" => 210.00,
"invoice_total" => 1210.00,
"amount_due" => 1210.00,
"payment_term" => "Payment within 30 days",
"payment_details" => [
[
"iban" => "BE68539007547034",
"swift" => "GEBABEBB",
"payment_reference" => "INV-2026-001"
]
]
];
$ch = curl_init("https://api.e-invoice.be/api/documents/");
curl_setopt_array($ch, [
CURLOPT_POST => true,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
"Authorization: Bearer " . getenv("E_INVOICE_API_KEY"),
"Content-Type: application/json",
],
CURLOPT_POSTFIELDS => json_encode($invoice),
]);
$body = curl_exec($ch);
$status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
if ($status >= 400) {
throw new RuntimeException("HTTP $status: $body");
}
print_r(json_decode($body, true));
```
```csharp C# theme={null}
using System.Net.Http.Headers;
using System.Text;
var invoice = """
{
"document_type": "INVOICE",
"invoice_id": "INV-2026-001",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"purchase_order": "PO-12345",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"vendor_email": "billing@e-invoice.be",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Professional services",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"subtotal": 1000.00,
"total_tax": 210.00,
"invoice_total": 1210.00,
"amount_due": 1210.00,
"payment_term": "Payment within 30 days",
"payment_details": [
{
"iban": "BE68539007547034",
"swift": "GEBABEBB",
"payment_reference": "INV-2026-001"
}
]
}
""";
using var client = new HttpClient { BaseAddress = new Uri("https://api.e-invoice.be") };
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
"Bearer", Environment.GetEnvironmentVariable("E_INVOICE_API_KEY"));
var response = await client.PostAsync(
"/api/documents/",
new StringContent(invoice, Encoding.UTF8, "application/json"));
var body = await response.Content.ReadAsStringAsync();
if (!response.IsSuccessStatusCode)
{
throw new HttpRequestException($"HTTP {(int)response.StatusCode}: {body}");
}
Console.WriteLine(body);
```
Replace the vendor fields with the data of your company. The API rejects a document on create (`406`) if the Peppol ID of the vendor is not one of the Peppol IDs of your company.
The API returns `201` with the document in state `DRAFT`. The response contains the calculated totals as strings:
```json Response (shortened) theme={null}
{
"id": "doc-1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d",
"created_at": "2026-10-01T09:30:00Z",
"document_type": "INVOICE",
"state": "DRAFT",
"direction": "OUTBOUND",
"invoice_id": "INV-2026-001",
"currency": "EUR",
"subtotal": "1000.00",
"total_discount": "0.00",
"total_tax": "210.00",
"invoice_total": "1210.00",
"amount_due": "1210.00"
}
```
Validation is not a separate mandatory call. `POST /api/documents/` rejects a payload that does not pass the same rules. Use `POST /api/validate/json` while you develop, because it returns all rule failures and the generated UBL.
Many examples on this page are fragments: they show only the `items`, `allowances` or `charges` part of the body. Add them to a complete document before you send them.
## Document-level allowances
A document-level allowance decreases the invoice amount after the line items are added together.
### Early payment discount
```json theme={null}
{
"document_type": "INVOICE",
"invoice_id": "INV-2026-010",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Product A",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"allowances": [
{
"amount": 50.00,
"reason": "Early payment discount (5%)",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
Calculation:
* Line items: €1,000.00
* Allowance: -€50.00
* `subtotal`: €950.00
* `total_tax` (21%): €199.50
* `invoice_total`: €1,149.50
### More than one document-level allowance
```json theme={null}
{
"allowances": [
{
"amount": 50.00,
"reason": "Volume discount",
"tax_code": "S",
"tax_rate": "21.00"
},
{
"amount": 25.00,
"reason": "Promotional discount",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
Calculation with line items of €1,000.00:
* Volume discount: -€50.00
* Promotional discount: -€25.00
* `subtotal`: €925.00
* `total_tax` (21%): €194.25
* `invoice_total`: €1,119.25
To state an allowance as a percentage, refer to [Percentage allowances and charges](#percentage-allowances-and-charges).
## Document-level charges
A document-level charge increases the invoice amount.
### Shipping fee
```json theme={null}
{
"document_type": "INVOICE",
"invoice_id": "INV-2026-011",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Product B",
"quantity": 5,
"unit": "C62",
"unit_price": 200.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"charges": [
{
"amount": 25.00,
"reason": "Shipping and handling",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
Calculation:
* Line items: €1,000.00
* Charge: +€25.00
* `subtotal`: €1,025.00
* `total_tax` (21%): €215.25
* `invoice_total`: €1,240.25
### More than one charge
```json theme={null}
{
"charges": [
{
"amount": 25.00,
"reason": "Shipping",
"tax_code": "S",
"tax_rate": "21.00"
},
{
"amount": 15.00,
"reason": "Insurance",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
## Combine allowances and charges
One invoice can contain allowances and charges:
```json theme={null}
{
"document_type": "INVOICE",
"invoice_id": "INV-2026-012",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Product C",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"allowances": [
{
"amount": 100.00,
"reason": "Bulk purchase discount (10%)",
"tax_code": "S",
"tax_rate": "21.00"
}
],
"charges": [
{
"amount": 30.00,
"reason": "Express delivery",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
Calculation:
* Line items: €1,000.00
* Allowance: -€100.00
* Charge: +€30.00
* `subtotal`: €930.00
* `total_tax` (21%): €195.30
* `invoice_total`: €1,125.30
## Line-level allowances
A line-level allowance applies to one line item.
The `amount` of a line is the net amount of the line: `quantity × unit_price`, minus the allowances of the line, plus the charges of the line. The API writes `amount` to the UBL as the line amount, and calculates the document totals from `quantity`, `unit_price` and the line allowances and charges. Make sure that the two results are equal.
### Discount on one product
```json theme={null}
{
"items": [
{
"description": "Product D",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 900.00,
"tax_rate": "21.00",
"allowances": [
{
"amount": 100.00,
"reason": "10% discount on this product"
}
]
},
{
"description": "Product E",
"quantity": 5,
"unit": "C62",
"unit_price": 50.00,
"amount": 250.00,
"tax_rate": "21.00"
}
]
}
```
Calculation:
* Line 1: (10 × €100) - €100 = €900.00
* Line 2: 5 × €50 = €250.00
* `subtotal`: €1,150.00
* `total_tax` (21%): €241.50
* `invoice_total`: €1,391.50
A line-level allowance or charge uses the tax rate of its line. It has no tax category of its own in the UBL.
### More than one allowance on one line
```json theme={null}
{
"items": [
{
"description": "Product F",
"quantity": 20,
"unit": "C62",
"unit_price": 100.00,
"amount": 1850.00,
"tax_rate": "21.00",
"allowances": [
{
"amount": 100.00,
"reason": "Volume discount (5%)"
},
{
"amount": 50.00,
"reason": "Loyalty programme discount"
}
]
}
]
}
```
Calculation of line 1:
* Base: 20 × €100 = €2,000.00
* Volume discount: -€100.00
* Loyalty discount: -€50.00
* Line amount: €1,850.00
## Line-level charges
A line-level charge applies to one line item.
```json theme={null}
{
"items": [
{
"description": "Fragile equipment",
"quantity": 1,
"unit": "C62",
"unit_price": 500.00,
"amount": 550.00,
"tax_rate": "21.00",
"charges": [
{
"amount": 50.00,
"reason": "Special handling - fragile item"
}
]
}
]
}
```
Calculation of line 1:
* Base: 1 × €500 = €500.00
* Special handling: +€50.00
* Line amount: €550.00
## Complete example with the two levels
This invoice uses allowances and charges at document level and at line level:
```json theme={null}
{
"document_type": "INVOICE",
"invoice_id": "INV-2026-013",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"payment_term": "Net 30 days",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Premium product A",
"quantity": 20,
"unit": "C62",
"unit_price": 100.00,
"amount": 1800.00,
"tax_rate": "21.00",
"allowances": [
{
"amount": 200.00,
"reason": "Bulk discount (10%)"
}
]
},
{
"description": "Standard product B",
"quantity": 10,
"unit": "C62",
"unit_price": 50.00,
"amount": 500.00,
"tax_rate": "21.00"
},
{
"description": "Heavy equipment",
"quantity": 1,
"unit": "C62",
"unit_price": 1000.00,
"amount": 1100.00,
"tax_rate": "21.00",
"charges": [
{
"amount": 100.00,
"reason": "Oversized item handling"
}
]
}
],
"allowances": [
{
"amount": 150.00,
"reason": "Early payment discount",
"tax_code": "S",
"tax_rate": "21.00"
}
],
"charges": [
{
"amount": 50.00,
"reason": "Delivery service",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
Line items:
* Line 1: (20 × €100) - €200 = €1,800.00
* Line 2: 10 × €50 = €500.00
* Line 3: €1,000 + €100 = €1,100.00
* Sum of the lines: €3,400.00
Document level:
* Allowance: -€150.00
* Charge: +€50.00
* `subtotal`: €3,300.00
* `total_discount`: €150.00
Tax and total:
* `total_tax` (21% of €3,300.00): €693.00
* `invoice_total`: €3,993.00
## Tax on allowances and charges
Each document-level allowance and charge has a `tax_rate` (default `21.00`) and a `tax_code` (default `S`). The API adds the amount to the tax base of the lines that have the same `tax_rate`.
### Same tax rate
If all lines have one tax rate, use that rate for the allowance or charge:
```json theme={null}
{
"items": [
{
"description": "Product A",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"allowances": [
{
"amount": 50.00,
"reason": "Volume discount",
"tax_rate": "21.00",
"tax_code": "S"
}
]
}
```
### Different tax rates
If the invoice has more than one tax rate, give each allowance or charge the rate of the lines to which it applies:
```json theme={null}
{
"items": [
{
"description": "Standard rate item",
"quantity": 1,
"unit": "C62",
"unit_price": 100.00,
"amount": 100.00,
"tax_rate": "21.00"
},
{
"description": "Reduced rate item",
"quantity": 1,
"unit": "C62",
"unit_price": 50.00,
"amount": 50.00,
"tax_rate": "6.00"
}
],
"allowances": [
{
"amount": 50.00,
"reason": "General discount on standard rate items",
"tax_rate": "21.00",
"tax_code": "S"
}
]
}
```
### Allowances and charges without VAT
For an allowance or charge on items that are exempt from VAT, send `tax_rate` `0.00` and the applicable tax category code:
```json theme={null}
{
"allowances": [
{
"amount": 100.00,
"reason": "Discount on exempt items",
"tax_rate": "0.00",
"tax_code": "E"
}
]
}
```
An allowance or charge with `tax_rate` `0.00` changes `subtotal` but does not change `total_tax`.
## Validation of the result
The API converts the JSON body to a Peppol BIS Billing 3.0 document. The rules of that standard depend on the content of the invoice: the country of the vendor, the document type, the tax category codes and the tax rates. For example, each document-level allowance must have a reason or a reason code, and its tax category must agree with its rate.
Validation is not a separate mandatory call. `POST /api/documents/` rejects a payload that does not pass the same rules. Use `POST /api/validate/json` while you develop, because it returns all rule failures and the generated UBL.
Refer to the [validation guide](/guides/validation) for the response format and to [Errors and troubleshooting](/guides/errors) for the rules that fail most frequently.
## Recommended practices
Give each allowance and charge a reason that the customer can understand.
Clear:
```json theme={null}
{
"reason": "Early payment discount (2% if paid within 10 days)"
}
```
Not clear:
```json theme={null}
{
"reason": "Discount"
}
```
Use the document level when the allowance or charge applies to the full order:
* Early payment discounts
* Shipping for the full order
* Promotional discounts on the full order
Use the line level when it applies to one product:
* Bulk discount on one product
* Special handling for a fragile item
* Promotion on one product
When you calculate an amount from a percentage, round the result to 2 decimals before you send it:
```javascript theme={null}
const lineItemsTotal = 1000.0;
const discountPercent = 5;
const discountAmount =
Math.round(lineItemsTotal * (discountPercent / 100) * 100) / 100; // 50.00
```
Give each document-level allowance and charge the tax category code and the tax rate of the items to which it applies.
When you give an early payment discount, state the terms in `payment_term`:
```json theme={null}
{
"payment_term": "Net 30 days. 2% discount if paid within 10 days.",
"allowances": [
{
"amount": 50.00,
"reason": "Early payment discount (2%)",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
## Frequent cases
```json theme={null}
{
"items": [
{
"description": "Product X",
"quantity": 100,
"unit": "C62",
"unit_price": 10.00,
"amount": 900.00,
"tax_rate": "21.00",
"allowances": [
{
"amount": 100.00,
"reason": "Volume discount - 100+ units (10%)"
}
]
}
]
}
```
```json theme={null}
{
"charges": [
{
"amount": 15.00,
"reason": "Standard shipping",
"tax_code": "S",
"tax_rate": "21.00"
},
{
"amount": 5.00,
"reason": "Handling fee",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
```json theme={null}
{
"allowances": [
{
"amount": 25.00,
"reason": "Gold member discount (5%)",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
```json theme={null}
{
"charges": [
{
"amount": 2.50,
"reason": "Credit card processing fee (2.5%)",
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
## Percentage allowances and charges
To state an allowance or a charge as a percentage, send `multiplier_factor` and `base_amount` together with `amount`. `multiplier_factor` is the percentage (send `10` for 10%; minimum 0, maximum 100, 2 decimals maximum).
The API does not calculate `amount` from `multiplier_factor` and `base_amount`, and it does not compare the three values. You must send `amount` (`base_amount × multiplier_factor / 100`, rounded to 2 decimals).
```json theme={null}
{
"document_type": "INVOICE",
"invoice_id": "INV-2026-014",
"invoice_date": "2026-10-01",
"due_date": "2026-10-31",
"currency": "EUR",
"vendor_name": "E-INVOICE BV",
"vendor_tax_id": "BE1018265814",
"vendor_address": "Brusselsesteenweg 119/A, 1980 Zemst, BE",
"customer_name": "OpenPeppol VZW",
"customer_tax_id": "BE0848934496",
"customer_address": "Robert Schumanplein 6 bus 5, 1040 Brussel, BE",
"items": [
{
"description": "Professional services",
"quantity": 10,
"unit": "C62",
"unit_price": 100.00,
"amount": 1000.00,
"tax_rate": "21.00"
}
],
"allowances": [
{
"reason": "Volume discount",
"reason_code": "95",
"multiplier_factor": 10,
"base_amount": 1000.00,
"amount": 100.00,
"tax_code": "S",
"tax_rate": "21.00"
}
]
}
```
Totals that the API calculates: `subtotal` 900.00, `total_discount` 100.00, `total_tax` 189.00, `invoice_total` 1089.00.
A charge accepts the same three fields (`multiplier_factor`, `base_amount`, `amount`).
### Allowance reason codes
The `reason_code` of an allowance accepts these UNCL5189 codes (send the code as a string):
| Code | Meaning |
| - | - |
| `41` | Bonus for works ahead of schedule |
| `42` | Other bonus |
| `60` | Manufacturer's consumer discount |
| `62` | Due to military status |
| `63` | Due to work accident |
| `64` | Special agreement |
| `65` | Production error discount |
| `66` | New outlet discount |
| `67` | Sample discount |
| `68` | End-of-range discount |
| `70` | Incoterm discount |
| `71` | Point of sales threshold allowance |
| `88` | Material surcharge/deduction |
| `95` | Discount |
| `100` | Special rebate |
| `102` | Fixed long term |
| `103` | Temporary |
| `104` | Standard |
| `105` | Yearly turnover |
The `reason_code` of a charge accepts the UNCL7161 codes. The full list is in the `ChargeReasonCode` schema of the [API reference](/api-reference).
## Next Steps
Read how the API calculates and examines the totals
Create credit notes with allowances
Examine complex invoices while you develop
See all fields of a line item, an allowance and a charge
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